Get Current Pixel value using Scanline in Delphi

Question

Hey,

I am trying to get the current pixel in an image by a "OnMouseMove event" Using Scanline.

something equivalent to this:

Label1.Caption := IntToStr(Image1.Picture.Bitmap.Canvas.Pixels[X,Y]);

Any ideas ?

Answer 1

Scanlines are useful for quickly scanning the entire line, like in your other post. But if you want to get an arbitrary single pixel, the best way to do it is to use the code you've already got.

Answer 2

ScanLine returns a pointer to a packed array of pixels that constitutes one line of a bitmap. Using this pointer you can access these pixels fast.

ScanLine can't help if you need only one pixel.

Still you can use ScanLine here; assuming bitmap pixel format pf32bit:

Label1.Caption:= IntToStr(PIntegerArray(Image1.Picture.Bitmap.ScanLine[Y])^[X]);